Modular testing device for analyzing biological samples

ABSTRACT

A modular testing device includes a base unit and an expansion unit that communicates with the base unit. The expansion unit includes a housing, a receptacle in which a sample holder containing a biological sample and reagent mixture can be placed, and an optical assembly positioned in the housing. The optical assembly is configured to amplify and detect a signal from the biological sample and reagent mixture. Data that is collected in the optical assembly is communicated to the base unit.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a Continuation of U.S. application Ser. No.15/561,901, filed Sep. 26, 2017, which is a 35 U.S.C. § 371 U.S.National Phase application of International Patent Application No.PCT/US2016/024260, filed Mar. 25, 2016, which claims the benefit ofpriority to U.S. Provisional Application No. 62/138,157, filed on Mar.25, 2015, the disclosures of which are incorporated by reference intheir entireties.

BACKGROUND

The present invention relates to devices that are capable of analyzingbiological samples, and in particular, to a modular testing device foranalyzing biological samples.

Biological samples are typically tested in laboratories after thebiological samples are collected in the field. A number of steps aretaken to prepare the sample after it has been collected, includingmixing the sample with reaction buffers, dyes, and any other chemicalsolutions needed to prepare the sample for testing. During or aftersample preparation, testing equipment also needs to be prepared. Thiscan include warming up the equipment, calibrating the equipment for thespecific tests to be run, and running through any other initialprocedures required for the specific testing equipment being used. Oncethe sample and the equipment are prepared, the prepared sample can beplaced in the equipment for testing.

The typical process for testing biological samples described above hassignificant disadvantages. One disadvantage is that biological samplesneed to be collected in the field, brought into the laboratory, and thentested. This can present the following issues. One, the biologicalsample can be contaminated between the time when it was collected andtime that it is to be tested. Two, it can be discovered that not enoughbiological sample was collected in the field, preventing the testingfrom being complete. Three, it can be later discovered that thebiological samples that were taken are otherwise unsuitable for testing.When a biological sample is unsuitable for testing for any of the abovereasons, an additional biological sample will need to be collected inorder to complete the testing. This requires additional time, money, andother resources to complete.

To eliminate the problems discussed above, portable testing devices areavailable for analyzing biological samples in the field. One such deviceis disclosed in PCT Application No. PCT/US14/59487, filed on Oct. 7,2014, and entitled “Portable Testing Device For Analyzing BiologicalSamples,” the disclosure of which is incorporated by reference in itsentirety. In order to be portable, the testing devices need to be smallenough so that they can be easily transported. This limitation on thesize of portable testing devices limits the number of biological samplesthat can be tested at one time.

SUMMARY

A modular testing device includes a base unit and an expansion unit thatcommunicates with the base unit. The expansion unit includes a housing,a receptacle in which a sample holder containing a biological sample andreagent mixture can be placed, and an optical assembly positioned in thehousing. The optical assembly is configured to amplify and detect asignal from the biological sample and reagent mixture. Data that iscollected in the optical assembly is communicated to the base unit.

A modular testing device includes a base unit and an expansion unit thatcommunicates with the base unit. The base unit includes a housing withan integrated touchscreen display, a receptacle in which a sample holdercontaining a biological sample and reagent mixture can be placed, and anoptical assembly positioned in the housing. The optical assembly isconfigured to amplify and detect a signal from the biological sample andreagent mixture. The expansion unit includes a housing, a receptacle inwhich a sample holder containing a biological sample and reagent mixturecan be placed, and an optical assembly positioned in the housing. Theoptical assembly is configured to amplify and detect a signal from thebiological sample and reagent mixture.

A method of analyzing a biological sample and reagent mixture in amodular testing device includes preparing a biological sample andreagent mixture for testing and placing the biological sample andreagent mixture in a sample holder. The sample holder is placed in areceptacle in an expansion unit. An excitation and detection testsequence is begun to analyze the biological sample and reagent mixturein the expansion unit. Data is collected from the excitation anddetection test sequence in the expansion unit. The data is communicatedfrom the expansion unit to a base unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram of a first embodiment of a modular testing deviceincluding a base unit and an expansion unit.

FIG. 1B is a diagram of a second embodiment of a modular testing deviceincluding a base unit and an expansion unit.

FIG. 1C is a diagram of a third embodiment of a modular testing deviceincluding a base unit and an expansion unit.

FIG. 2A is a perspective view of a base unit.

FIG. 2B is a perspective view of the base unit when a sample holder inthe form of a tube array is being placed in the base unit.

FIG. 3 is a block diagram of the base unit.

FIG. 4 is a perspective view of an expansion unit.

FIG. 5 is a block diagram of the expansion unit.

FIG. 6A is a perspective view of an optical assembly.

FIG. 6B is a cross-sectional view of the optical assembly.

FIG. 7 is an exploded view of a heating portion of the optical assembly.

FIG. 8 is an exploded view of a lens portion of the optical assembly.

FIG. 9 is an exploded view of a housing portion of the optical assembly.

FIG. 10A is a partially exploded view of a first optical mountingportion of the optical assembly.

FIG. 10B is a partially exploded view of a second optical mountingportion of the optical assembly.

FIG. 10C is a partially exploded view of the first optical mountingportion and the second optical mounting portion of the optical assembly.

FIG. 11 is a flowchart showing steps for operating the modular testingdevice.

DETAILED DESCRIPTION

In general, the present disclosure relates to modular testing devicesfor analyzing biological samples. In the embodiments described below,the modular testing device is capable of testing biological samples withan isothermal amplification process, such as NEAR chemistry, LAMPchemistry, RPA chemistry, or NASBA chemistry. This eliminates the needfor thermocycling as a means to amplify nucleic acid products forendpoint detection.

FIG. 1A is a diagram of modular testing device 100 including base unit102 and expansion units 106. FIG. 1B is a diagram of modular testingdevice 100 including base unit 102 and expansion units 106. FIG. 1C is adiagram of modular testing device 100 including base unit 104 andexpansion units 106.

Modular testing device 100 includes a base unit, including either baseunit 102 or base unit 104, and one or more expansion units 106. In FIGS.1A-1B, modular testing device 100 is shown with base unit 102. Base unit102 can be used to analyze biological samples that have been mixed witha reaction mixture (also referred to as a biological sample and reagentmixture). Base unit 102 includes an optical assembly to amplify, excite,and detect a biological sample that is placed in base unit 102 fortesting. Base unit 102 further includes a power supply to power baseunit 102, an electronic assembly including components that are capableof running test protocol, and a screen that a user can interface with toselect parameters for the test protocol and which can display data as itis collected. In FIG. 1C, modular testing device 100 is shown with baseunit 104. Base unit 104 is a desktop computer in the embodiment shown,but can be a laptop computer, tablet computer, a mobile phone, a smartwatch, an embedded PC, or any other suitable computer in alternateembodiments. Base unit 104 includes a power supply to power base unit104, an electronic assembly including components that are capable ofrunning test protocols, a machine readable code reader, and a screenthat a user can interface with to select parameters for the testprotocol and which can display data as it is collected.

In the embodiment shown in FIGS. 1A-1C, three expansion units 106 areshown. In alternative embodiments, any number of expansion units 106 canbe used. Each expansion unit 106 includes an optical assembly toamplify, excite, and detect a biological sample that is placed in baseunit 102 for testing. In the embodiment shown in FIGS. 1A-1C, eachexpansion unit 106 further includes a power supply to power expansionunit 106. In an alternate embodiment, expansion unit 106 does not have apower supply but is instead powered by a base unit. Each expansion unit106 further includes an electronic assembly including components thatare capable of communicating data to the base unit. Each expansion unit106 interfaces with and is controlled by the base unit, either base unit102 or base unit 104. The base unit communicates with expansion units106 to indicate what testing is to be run in expansion units 106 andwhen testing is to be initiated. Expansion units 106 can be connected tothe base unit with a hard wire connection or expansion units 106 can beconnected to the base unit with a wireless connection. Testing can becompleted in each expansion unit 106 using the optical assembly and datacollected during the testing is communicated to the base unit. The datacan be processed in expansion units 106 before it is communicated to thebase unit or it can be communicated to the base unit before beingprocessed. Either way, the data can also be processed in the base unit.

In the embodiments shown in FIGS. 1A and 1C, a first expansion unit 106is connected to the base unit, a second expansion unit 106 is connectedto the first expansion unit 106, and a third expansion unit 106 isconnected to the second expansion unit 106. In the embodiment shown inFIG. 1B, expansion units 106 are each connected to the base unit.Further, in alternate embodiments, expansion units 106 can be connectedto one another or the base units can be connected to one another. In oneembodiment, for example, a first base unit 102 could be connected to asecond base unit 102. The first base unit 102 could communicate to thesecond base unit 102 what testing to run and when to initiate testing.The first base unit 102 and the second base unit 102 could conducttesting at the same time or at different times. In each of FIGS. 1A-1C,expansion units 106 and the base units can be connected using a hardwireconnection or a wireless connection.

Expansion units 106 can conduct testing of a biological sample at thesame time or at different times. For example, each expansion unit 106can be loaded with a biological sample. The base unit can then indicateto each expansion unit 106 that testing is to begin at the same time.Alternately, a first expansion unit 106 can be loaded with a biologicalsample and the base unit can indicate that the first expansion unit 106is to begin testing. A second expansion unit 106 can then be loaded witha biological sample and the base unit can then indicate that the secondexpansion unit 106 is to begin testing.

Expansion units 106 can test a biological sample using turbidity,fluorescence, chemiluminescence, thermoluminescence, photometric,absorbance, or radiometric means. Expansion units 106 can also rundifferent analytical methods, for example immunoassay, DNAamplification, mass spectrometry, or high-performance liquidchromatography. A single base unit can control expansion units 106 thatare using different tests and running different analytical methods.

Modular testing device 100 is advantageous, as it allows a user tocustomize its modular testing device 100 for different applications.Expansion units 106 can be used with base unit 102 when a user wants toconduct testing in the field. Expansion units 106 can also then be usedwith base unit 104 when a user is conducting testing in a laboratorysetting. Expansion units 106 also allow a user to customize how manytests are run during a testing protocol. Modular testing device 100 canalso include a rack that is capable of holding expansion units 106. Therack can be designed to fit over the base unit so that expansion units106 can be positioned on the rack over the base unit.

FIG. 2A is a perspective view of base unit 102. FIG. 2B is a perspectiveview of base unit 102 when a sample holder in the form of tube array 108is being placed in base unit 102. Base unit 102 includes housing 110(including first housing portion 112 and second housing portion 114),display 116, handle 118, lid 120, receptacle 122 (shown in FIG. 2B), andoptical assembly 124 (shown in FIG. 2B). FIG. 2B also shows tube array108.

Base unit 102 is used to analyze biological samples that have been mixedwith a reaction mixture (also referred to as a biological sample andreagent mixture). Housing 110 forms the body of base unit 102. Housing110 includes first housing portion 112 and second housing portion 114.First housing portion 112 forms a base portion of base unit 102 andsecond housing portion 114 forms a top portion of base unit 102. Locatedon a front top side of housing 110 is display 116. Display 116 is atouchscreen display in the embodiment shown, but can be any suitabledisplay in alternate embodiments. A user can use display 116 to selecttest protocol and set up the parameters for tests that will be run inbase unit 102. A user can also use display 116 to provide sample andassay traceability information to base unit 102. Display 116 will alsodisplay data that is collected during testing.

Housing 110 further includes handle 118. Handle 118 is located on afront side of housing 110 in the embodiment shown, but can be located inany suitable location in alternate embodiments. Handle 118 is shown asan integrated handle with housing 110 in the embodiment shown, but canbe attached to base unit 102 in any suitable manner in alternateembodiments. Handle 118 is included on base unit 102 so that base unit102 can be easily transported in the field.

As seen in FIG. 2B, receptacle 122 is located on a top side of base unit102 in the embodiment shown, but can be located in any suitable locationin alternate embodiments. Receptacle 122 is an opening in housing 110 ofbase unit 102. A sample holder containing a biological sample andreagent mixture can be placed in receptacle 122 for testing. In FIG. 2B,receptacle 122 is configured to receive tube array 108. In alternateembodiments, receptacle 122 can be configured in any manner that iscapable of receiving a sample holder.

Housing 110 also includes lid 120. Lid 120 is located on a top side ofhousing 110 in the embodiment shown, but can be located in any suitablelocation in alternate embodiments. Lid 120 is included on base unit 102to cover receptacle 122. When a sample holder is placed in receptacle122 of base unit 102 it will be positioned in optical assembly 124 thatis held in base unit 102. Optical assembly 124 is positioned just belowreceptacle 122 and can be accessed through receptacle 122. Opticalassembly 124 will be able to amplify, excite, and detect the biologicalsample in the sample holder. Optical assembly 124 includes a heatingcomponent that is used to heat the biological sample, causing it toamplify. The heating component can heat the biological sample at aconstant temperature or the heating component can cycle the biologicalsample through different temperatures. Optical assembly 124 will thenuse radiation to excite the biological sample, so that the biologicalsample with emit radiation.

Lid 120 is positioned over receptacle 122 to prevent radiation fromescaping housing 110 through receptacle 122. Lid 120 further preventsambient light from entering housing 110 through receptacle 122, whichprevents the ambient light from skewing or negating results of the teststhat are being run in base unit 102. Lid 120 also covers receptacle 122to prevent contamination from entering into receptacle 122 when baseunit 102 is being used in the field. Lid 120 is capable of being movedbetween an open and closed position and can be held in the closedposition with any suitable means. In the embodiment shown, lid 120 isheld in a closed position with magnets. When lid 120 is in an openposition, sample holders (including tube array 108) can be inserted intoand removed from receptacle 122. When lid 120 is closed, sample holderswill be held in receptacle 122 and radiation in base unit 102 will notescape from housing 110. When lid 120 is in a closed position, it putspressure on the sample holder that is placed in a heat block in baseunit 102. This improves engagement and heat transfer between the sampleholder and the heat block in base unit 102.

Receptacle 122 can be shaped to receive any sample holder, allowing baseunit 102 to be designed to accommodate a wide variety of standard andcustom designed sample holders. Tube array 108 is a standard sampleholder that is widely available on the market. A card can also be customdesigned for use as a sample holder that is to be used with base unit102. Receptacle 122 allows base unit 102 to be designed to accommodate awide variety of sample holder shapes and sizes.

Base unit 102 is designed for use in the field and provides manyadvantages for such use. Biological materials that are collected in thefield can be tested in the field as they are collected. This alleviatesconcerns about contamination or degradation of the biological sample, asthere is no need to transport the biological sample back to a laboratoryfor testing. Further, base unit 102 allows a user to quickly react toresults from tests that are run in the field. If a test is inconclusive,additional biological material can be collected and sampled right away.Further, if testing indicates that there is a pathogen or toxin in thesample, a user can initiate proper safety protocol right away to protectagainst the pathogen or toxin.

Base unit 102 includes a number of features that make it suitable foruse in the field. Handle 118 is included to easily transport the device.Display 116 is integrated into base unit 102 so that base unit 102 canact as an all-in-one system, as base unit 102 is capable of testing abiological sample, processing the data that is collected, and displayingthe data on display 116. Display 116 eliminates the need for base unit102 to be connected to another machine or computer to process anddisplay the results of testing. This can allow a user to avoid having tocarry an additional device in the field or having to wait till they getback to a laboratory to read the data. Base unit 102 includes all of thefeatures that are necessary for testing, processing, and displayingresults of the tests in a compact all-in-one device.

FIG. 3 is a block diagram of base unit 102. Base unit 102 includesdisplay 116, power supply 130, electronic assembly 132, machine readablecode reader 134, and optical assembly 124. Optical assembly 124 includesheat block 140, light-emitting diodes 142, and photodetectors 144.

Base unit 102 is used to analyze and obtain data from biological samplesin the field. To accomplish this, base unit 102 is equipped with display116, power supply 130, electronic assembly 132, machine readable codereader 134, and optical assembly 124. In the embodiment shown, display116 is a touchscreen display that acts as a primary user interfacebetween a user and base unit 102. A user can input information intodisplay 116 to indicate what testing should be run in base unit 102 foreach biological sample. Further, a user can monitor the results of teststhat are run in base unit 102 on display 116.

Display 116 is connected to electronic assembly 132 with interfacecircuitry. Information that is inputted into display 116 will becommunicated to electronic assembly 132 using the interface circuitry.Electronic assembly 132 includes hardware, firmware, and software tocontrol the operations of base unit 102, including a microprocessor.Electronic assembly 132 will indicate what testing is to be run in baseunit 102 and communicates this information throughout the device. Datathat is collected in base unit 102 during testing will also becommunicated to electronic assembly 132. Electronic assembly 132 canprocess this data and transmit it to display 116 to be displayed.Electronic assembly 132 further stores this data for retrieval ortransfer at a later time.

Electronic assembly 132 is connected to power supply 130 with interfacecircuitry. Power supply 130 includes components that are capable ofpowering base unit 102, including a battery, a power board, a powerswitch, and a power jack that can be connected to a power source forrecharging. Power from power supply 130 is sent to electronic assembly132 through the interface circuitry so that base unit 102 can operate.

Base unit 102 can further include machine readable code reader 134. Whena sample holder containing a machine readable code is placed in baseunit 102, machine readable code reader 134 can read the machine readablecode on the sample holder. A machine readable code can also be providedseparate from the sample holder. The machine readable code can containall of the parameters for the testing protocol and the assaytraceability information for the test that is to be run. Alternatively,the machine readable code can indicate what test is to be run. This isadvantageous, as it allows a user to insert a sample into base unit 102and base unit 102 will automatically select a test protocol and begintesting.

Electronic assembly 132 includes a microprocessor, associated memory,and interface circuitry for interfacing with display 116 and opticalassembly 124. Input that is received in electronic assembly 132 fromdisplay 116 can be processed in electronic assembly 132. Thisinformation can be used to control optical assembly 124. Opticalassembly 124 conducts testing of the biological sample that is placed inbase unit 102. As the testing is being completed, data that is collectedin optical assembly 124 can be communicated to electronic assembly 132.Electronic assembly 132 processes this data and can transmit the data todisplay 116 so that the user can monitor the test results. Electronicassembly 132 can also transmit the data to an external device with anysuitable data transfer means, including wireless transfer or transferthrough a USB port, microUSB port, SD card, or microSD card.

Optical assembly 124 includes heat block 140, light-emitting diodes 142,and photodetectors 144 to conduct testing of the biological samples thatare placed in base unit 102. Optical assembly 124 will amplify thebiological sample using heat and will then excite the biological samplewith radiation to detect the presence of a specific fluorescent marker.Biological samples that are placed in base unit 102 will be mixed with areaction mixture that contains one or more fluorescent dyes. When thebiological sample is placed in base unit 102, heat block 140 willamplify the biological sample with heat. Heat block 140 is positionedunderneath receptacle 122 in base unit 102 so that when a sample holdercontaining a biological sample is placed in base unit 102, the sampleholder will be positioned in heat block 140. As the biological sample isamplified it can be analyzed using light-emitting diodes 142 andphotodetectors 144. Light-emitting diodes 142 transmit radiation to thebiological sample to excite the biological sample. A plurality oflight-emitting diodes 142 can be used in base unit 102 to excite thebiological sample at a predetermined cycle rate. In the embodimentshown, the plurality of light-emitting diodes 142 cycle on and off at1.54 kHz. In alternate embodiments, light-emitting diodes 142 can cycleat any predetermined cycle rate. When the biological sample is excitedat the predetermined cycle rate, it will emit radiation at the samepredetermined cycle rate and the corresponding wavelengths of thefluorescent dyes that were added to the biological sample. Thisradiation can be received by photodetectors 144. A plurality ofphotodetectors 144 can be used in base unit 102 to read the emittedradiation from the biological sample at different radiation wavelengths.The signals produced by photodetectors 144 can then be transmitted toelectronic assembly 132 for processing and analysis, and displayed ondisplay 116 as data collected during testing.

Base unit 102 is advantageous, as it is an all-in-one device. Base unit102 includes optical assembly 124 to conduct testing of biologicalsamples in the field. Base unit 102 further includes electronic assembly132 and display 116 to specify what testing to run and to process anddisplay data that is collected during testing. Base unit 102 furtherincludes power supply 130, including a battery, so that base unit 102can be used in the field. Base unit 102 includes every component that isnecessary to conduct testing of a biological sample, and does so in acompact device that can be easily used in the field. Using base unit 102in the field prevents concerns about contamination or degradation ofbiological samples and allows a user to quickly react to test results inthe field.

FIG. 4 is a perspective view of expansion unit 106. Expansion unit 106includes housing 150 (including first housing portion 152 and secondhousing portion 154), lid 156, receptacle 158, and optical assembly 124.

Expansion unit 106 is used to analyze biological samples that have beenmixed with a reaction mixture (also referred to as a biological sampleand reagent mixture). Housing 150 forms the body of expansion unit 106.Housing 150 includes first housing portion 152 and second housingportion 154. First housing portion 152 forms a base portion of expansionunit 106 and second housing portion 154 forms a top portion of expansionunit 106. Expansion unit 106 further includes lid 156.

Receptacle 158 is located on a top side of expansion unit 106 in theembodiment shown, but can be located in any suitable location inalternate embodiments. Receptacle 158 is an opening in housing 150 ofexpansion unit 106. A sample holder containing a biological sample canbe placed in receptacle 158 for testing. In the embodiment shown,receptacle 158 is configured to receive tube array 108 (not shown inFIG. 4). In alternate embodiments, receptacle 158 can be configured inany manner that is capable of receiving a sample holder.

Housing 150 also includes lid 156. Lid 156 is located on a top side ofhousing 150 in the embodiment shown, but can be located in any suitablelocation in alternate embodiments. Lid 150 is included on expansion unit106 to cover receptacle 158. When a sample holder is placed inreceptacle 158 of expansion unit 106 it will be positioned in opticalassembly 124 that is held in expansion unit 106. Optical assembly 124 ispositioned just below receptacle 158 and can be accessed throughreceptacle 158. Optical assembly 124 will be able to amplify, excite,and detect the biological sample in the sample holder. In the embodimentshown in FIG. 4, optical assembly 124 includes a heating component anddetection components. The heating component is used to heat thebiological sample, causing it to amplify. The heating component can heatthe biological sample at a constant temperature or the heating componentcan cycle the biological sample through different temperatures. Opticalassembly 124 will then use radiation to excite the biological sample, sothat the biological sample with emit radiation which can then bedetected by the detection components. In alternate embodiments,expansion unit 106 can include only a heating component or onlydetection components. Further, the heating component can heat thebiological sample at a constant temperature, the heating component cancool the biological sample at a constant temperature, or the heatingcomponent can cycle the biological sample through a cycle of differenttemperatures.

Lid 156 is positioned over receptacle 158 to prevent radiation fromescaping housing 150 through receptacle 158. Lid 156 further preventsambient light from entering housing 150 through receptacle 158, whichprevents the ambient light from skewing or negating results of the teststhat are being run in expansion unit 106. Lid 156 also covers receptacle158 to prevent contamination from entering into receptacle 158 whenexpansion unit 106 is being used in the field. Lid 156 is capable ofbeing moved between an open and closed position and can be held in theclosed position with any suitable means. When lid 156 is in an openposition, sample holders (including tube array 108) can be inserted intoand removed from receptacle 158. When lid 156 is closed, sample holderswill be held in receptacle 158 and radiation in expansion unit 106 willnot escape from housing 150. When lid 156 is in a closed position, itputs pressure on the sample holder that is placed in a heat block inexpansion unit 106. This improves engagement and heat transfer betweenthe sample holder and the heat block in expansion unit 106.

Receptacle 158 can be shaped to receive any sample holder, allowingexpansion unit 106 to be designed to accommodate a wide variety ofstandard and custom designed sample holders. Tube array 108 is astandard sample holder that is widely available on the market. A cardcan also be custom designed for use as a sample holder that is to beused with expansion unit 106. Receptacle 158 allows expansion unit 106to be designed to accommodate a wide variety of sample holder shapes andsizes.

Expansion unit 106 is advantageous, as it allows a user to increase theamount of tests the user is running in any given situation. Expansionunit 106 can be used in a laboratory setting or in the field. Expansionunit 106 can interface with a base unit, where the base unit indicateswhat testing the expansion unit 106 should conduct and when the testingshould begin. Once data is collected in expansion unit 106, it can becommunicated to the base unit. The data can be processed in expansionunit 106 before it is communicated to the base unit or it can becommunicated to the base unit without being processed. The base unit canthen run the test protocol to process the data.

FIG. 5 is a block diagram of expansion unit 106. Expansion unit 106includes power supply 160, electronic assembly 162, and optical assembly124. Optical assembly 124 includes heat block 140, light-emitting diodes142, and photodetectors 144.

Expansion unit 106 is used to analyze and obtain data from biologicalsamples. To accomplish this, expansion unit 106 is equipped with powersupply 160, electronic assembly 162, and optical assembly 124.Electronic assembly 162 includes hardware, firmware, and software tocontrol the operations of expansion unit 106, including amicroprocessor. Electronic assembly 162 also includes a communicationinterface that communicates with an electronic assembly in the baseunit. The communication interface can be a hard wire interface or awireless interface. The wireless interface can communicate viaBluetooth, Wi-Fi, Infrared, or any other wireless technology.

The electronic assembly in the base unit will indicate what testing isto be run in expansion unit 106 and will communicates this informationto electronic assembly 162 in expansion unit 106. Data that is collectedin expansion unit 106 during testing will be communicated to electronicassembly 162 in expansion unit 106. Electronic assembly 162 in expansionunit 106 will then communicate the data to the electronic assembly inthe base unit. Data can be processed in expansion unit 106 before it iscommunicated to the base unit or it can be communicated to the base unitwithout being processed. The electronic assembly in the base unit canalso process this data and transmit it to a display to be displayed. Theelectronic assembly in the base unit also stores this data for retrievalor transfer at a later time.

In one embodiment, expansion unit 106 could be docked to a base unitthrough hard wire interface circuitry. When expansion unit 106 is dockedto the base unit, the base unit can provide instructions to expansionunit 106 through the hard wire interface circuitry. Expansion unit 106can then be removed from the base unit and used to run tests. Aftertesting is completed, expansion unit 106 can be docked to the base unitthrough the hard wire interface circuitry again to communicate the datacollected during the testing to the base unit. In a second embodiment,expansion unit 106 can receive instructions from a base unit wirelesslyby utilizing wireless interface circuitry. Expansion unit 106 can thenbe used to run tests. After testing is completed, expansion unit 106 canbe docked to the base unit through hard wire interface circuitry tocommunicate the data collected during the testing to the base unit.

Electronic assembly 162 is connected to power supply 160 with interfacecircuitry. In the embodiment shown in FIG. 5, power supply 160 includescomponents that are capable of powering expansion unit 106, including abattery, a power board, a power switch, and a power jack that can beconnected to a power source for recharging. Power from power supply 160is sent to electronic assembly 162 through the interface circuitry sothat expansion unit 106 can operate. In an alternate embodiment,expansion unit 106 can be powered by a base unit and power supply 160will include a power jack that can be connected to the base unit toprovide power to expansion unit 106.

Electronic assembly 162 further includes a microprocessor, associatedmemory, and interface circuitry for interfacing with optical assembly124. Input that is received in electronic assembly 162 from theelectronic assembly of the base unit can be processed in electronicassembly 162. This information can be used to control optical assembly124. Optical assembly 124 conducts testing of the biological sample thatis placed in expansion unit 106. As the testing is being completed, datathat is collected in optical assembly 124 can be communicated toelectronic assembly 162. Electronic assembly 162 processes this data andcan transmit the data to the electronic assembly in the base unit. Theelectronic assembly in the base unit can then transmit the data to adisplay so that the user can monitor the test results. Electronicassembly 162 can also transmit the data to an external device with anysuitable data transfer means, including wireless transfer or transferthrough a USB port, microUSB port, SD card, or microSD card.

Optical assembly 124 includes heat block 140, light-emitting diodes 142,and photodetectors 144 to conduct testing of the biological samples thatare placed in expansion unit 106. Optical assembly 124 will amplify thebiological sample using heat and will then excite the biological samplewith radiation to detect the presence of a specific fluorescent marker.Biological samples that are placed in expansion unit 106 will be mixedwith a reaction mixture that contains one or more fluorescent dyes. Whenthe biological sample is placed in expansion unit 106, heat block 140will amplify the biological sample with heat. Heat block 140 ispositioned underneath receptacle 158 in expansion unit 106 so that whena sample holder containing a biological sample is placed in expansionunit 106, the sample holder will be positioned in heat block 140. As thebiological sample is amplified it can be analyzed using light-emittingdiodes 142 and photodetectors 144. Light-emitting diodes 142 transmitradiation to the biological sample to excite the biological sample. Aplurality of light-emitting diodes 142 can be used in expansion unit 106to excite the biological sample at a predetermined cycle rate. In theembodiment shown, the plurality of light-emitting diodes 142 cycle onand off at 1.54 kHz. In alternate embodiments, light-emitting diodes 142can cycle at any predetermined cycle rate. When the biological sample isexcited at the predetermined cycle rate, it will emit radiation at thesame predetermined cycle rate and the corresponding wavelengths of thefluorescent dyes that were added to the biological sample. Thisradiation can be received by photodetectors 144. A plurality ofphotodetectors 144 can be used in expansion unit 106 to read the emittedradiation from the biological sample at different radiation wavelengths.The signals produced by photodetectors 144 can then be transmitted toelectronic assembly 162 for transmitting to the electronic assembly ofthe base unit. The electronic assembly of the base unit can then processand analyze the data, and display the data as the data is collectedduring testing.

FIG. 6A is a perspective view of optical assembly 124. FIG. 6B is across-sectional view of optical assembly 124. Optical assembly 124includes heating portion 170 (not shown in FIG. 6A), lens portion 172(not shown in FIG. 6A), housing portion 174, first optical mountingportion 176, and second optical mounting portion 178. Also shown in FIG.6B is tube array 108.

Optical assembly 124 can be positioned in both base unit 102 andexpansion units 106. Optical assembly 124 includes heating portion 170to heat the biological sample and reagent mixture in tube array 108.Positioned in heating portion 170 is lens portion 172 to directradiation through optical assembly 124. Housing portion 174 ispositioned around heating portion 170 and forms the main body portion ofoptical assembly 124. First optical mounting portion 176 is positionedon a first side of housing portion 174 and second optical mountingportion 178 is positioned on a second side of housing portion 174. Bothfirst optical mounting portion 176 and second optical mounting portion178 mount light-emitting diodes to optical assembly 124 to excite thebiological sample and reagent mixture in tube array 108. Further, bothfirst optical mounting portion 176 and second optical mounting portion178 mount photodetectors to optical assembly 124 to detect a signal fromthe biological sample and reagent mixture in tube array 108.

FIG. 7 is an exploded view of heating portion 170 of optical assembly124. As seen in FIGS. 6B and 7, heating portion 170 includes sampleblock 190, heating component 192, temperature sensor 194, wells 196,passages 198, passages 200, passages 202, and passages 204.

Heating portion 170 includes sample block 190 that forms the main bodyportion of heating portion 170. Heating component 192 is attached to asecond side of sample block 190. Heating component 192 is a flatpolyimide heater in the embodiment shown, but can be any suitable heaterin alternate embodiments. Temperature sensor 194 is placed in a bottomportion of sample block 190 to sense the temperature of sample block190. Further, in alternate embodiments, a thermal cut out switch, suchas a PEPI switch, can be placed in series with a lead on heatingcomponent 192.

Sample block 190 includes wells 196 on a top side of sample block 190.Each well 196 is sized to receive one tube in tube array 108. In theembodiment shown in FIG. 7, heating component 192 heats each of wells196 at a constant temperature so that modular testing device 100 can beused with isothermal amplification chemistries. In alternateembodiments, heating component 192 can heat each well 196 at a differenttemperature across a gradient, or there can be a plurality of heatingcomponents so that each well is heated by a different heating componentto a different temperature. This allows a user to conduct a preliminarytest to determine what temperature should be used to analyze aparticular biological sample. In further alternate embodiments, heatingcomponent 192 can include a thermal cycler that is capable of cyclingheating potion 170 through different temperatures so that modulartesting device 100 can be used with non-isothermal polymerase chainreaction (PCR) chemistries.

Sample block 190 further includes passages 198, passages 200, passages202, and passages 204. Passages 198 extend from a first side of sampleblock 190 to wells 196. Passages 200 extending from a bottom side ofsample block 190 to wells 196. Passages 202 extend from the second sideof sample block 190 to wells 196. Passages 204 extend from a bottom sideof sample block 190 to wells 196. Passages 198, passages 200, passages202, and passages 204 extend through sample block 190 to directradiation into and out of the biological sample and reagent mixture intube array 108 in wells 196.

FIG. 8 is an exploded view of lens portion 172 of optical assembly 124.As seen in FIGS. 6B and 8, lens portion 172 includes lenses 210 and lensretainer 212.

Lens portion 172 includes lenses 210 that are positioned in sample block190 of heating portion 170. Passages 198 in sample block 190 are sizedto receive lenses 210 on the first side of sample block 190. One lens210 is positioned in each passage 198 of sample block 190. Lenses 210are held in passages 198 with lens retainer 212. Lens retainer 212 has aplurality of apertures so that radiation can pass through lens retainer212 to pass through lenses 210.

FIG. 9 is an exploded view of housing portion 174 of optical assembly124. As seen in FIGS. 6A-6B and 9, housing portion 174 includes firsthousing 220, second housing 222, heat shield 224, passages 226, passages228, passages 230, passages 232, and apertures 234.

Housing portion 174 includes first housing 220 positioned on a firstside of heating portion 170 and second housing 222 positioned on asecond side of heating portion 170. First housing 220 and second housing222 form a main body portion of housing portion 174. Heat shield 224 ispositioned between first housing 220 and second housing 222 on a topside of heating portion 170.

First housing 220 includes passages 226 and passages 228. Passages 226extend from a first side of first housing 220 to an interior side offirst housing 220 adjacent sample block 190. Each passage 226 in firsthousing 220 is aligned with one passage 198 in sample block 190.Passages 228 extend from a bottom side of first housing 220 to aninterior side of first housing 220 adjacent sample block 190. Eachpassage 228 in first housing 220 is aligned with one passage 200 insample block 190. Passages 226 and 228 extend through first housing 220to direct radiation into and out of the biological sample and reagentmixture in tube array 108 in wells 196 of sample block 190.

Second housing 222 includes passages 230 and passages 232. Passages 230extend from a second side of second housing 222 to an interior side ofsecond housing 222 adjacent sample block 190. Each passage 230 in secondhousing 222 is aligned with one passage 202 in sample block 190.Passages 232 extend from a bottom side of second housing 222 to aninterior side of second housing 222 adjacent sample block 190. Eachpassage 232 in second housing 222 is aligned with one passage 204 insample block 190. Passages 230 and 232 extend through second housing 222to direct radiation into and out of the biological sample and reagentmixture in tube array 108 in wells 196 of sample block 190.

Heat shield 224 is positioned over sample block 190 and held betweenfirst housing 220 and second housing 222. Apertures 234 extend from atop side to a bottom side of heat shield 224. Each aperture 234 in heatshield 224 is aligned with one well 196 in sample block 190. This allowstube array 108 to be positioned in wells 196 in sample block 190 throughapertures 234 in heat shield 224. Heat shield 224 is positioned oversample block 190 to prevent heat from escaping out of the top side ofsample block 190.

Heat shield 224 further provides an insulated surface to protect theuser from the top side of sample block 190 when sample block 190 is hot.

FIG. 10A is a partially exploded view of first optical mounting portion176 of optical assembly 124. FIG. 10B is a partially exploded view ofsecond optical mounting portion 178 of optical assembly 124. FIG. 10C isa partially exploded view of first optical mounting portion 176 andsecond optical mounting portion 178 of optical assembly 124. As seen inFIGS. 6A-6B, 10A, and 10C, first optical mounting portion 176 includeshousing 240, housing 242, emission filter 244, gasket 246, excitationfilter 248, passages 250, passages 252, photodetectors mounting board254, photodetectors 256, gasket 258, light-emitting diodes mountingboard 260, light-emitting diodes 262, and gasket 264. As seen in FIGS.6A-6B and 10B-10C, second optical mounting portion 178 includes housing270, housing 272, emission filter 274, gasket 276, excitation filter278, passages 280, passages 282, photodetectors mounting board 284,photodetectors 286, gasket 288, light-emitting diodes mounting board290, light-emitting diodes 292, and gasket 294.

First optical mounting portion 176 is positioned on a first side ofhousing portion 174. First optical mounting portion 176 includes housing240 and housing 242 that form a main body portion of first opticalmounting portion 176. Housing 240 is attached to a first side of firsthousing 220 of housing portion 174. Emission filter 244 is positionedbetween housing 240 and first housing 220 in a groove on the first sideof first housing 220. Gasket 246 is positioned between emission filter244 and housing 240. Housing 242 is attached to a bottom side of firsthousing 220 of housing portion 174. Excitation filter 248 is positionedbetween housing 242 and first housing 220 in a groove on the bottom sideof first housing 220.

Housing 240 includes passages 250. Passages 250 extend from a first sideof housing 240 to an interior side of housing 240 adjacent first housing220. Each passage 250 in housing 240 is aligned with one passage 226 infirst housing 220. Housing 242 includes passages 252. Passages 252extend from a bottom side of housing 252 to an interior side of housing242 adjacent first housing 220. Each passage 252 in housing 242 isaligned with one passage 228 in first housing 220.

Photodetectors mounting board 254 is connected to a first side ofhousing 240. Photodetectors mounting board 254 is an electronic boardthat includes photodetectors 256. Each photodetector 256 onphotodetectors mounting board 254 is positioned in one passage 250 inhousing 240. Gasket 258 is positioned between photodetectors mountingboard 254 and housing 240. Light-emitting diodes mounting board 260 isattached to a bottom side of housing 242. Light-emitting diodes mountingboard 260 is an electronic board that includes light-emitting diodes262. Each light-emitting diode 262 on light-emitting diodes mountingboard 260 is positioned in one passage 252 in housing 242. Gasket 264 ispositioned between light-emitting diodes mounting board 260 and housing242.

Second optical mounting portion 178 is positioned on a second side ofhousing portion 174. Second optical mounting portion 178 includeshousing 270 and housing 272 that form a main body portion of secondoptical mounting portion 178. Housing 270 is attached to a second sideof second housing 222 of housing portion 174. Emission filter 274 ispositioned between housing 270 and second housing 222 in a groove on thesecond side of second housing 222. Gasket 276 is positioned betweenemission filter 274 and housing 270. Housing 272 is attached to a bottomside of second housing 222 of housing portion 174. Excitation filter 278is positioned between housing 272 and second housing 222 in a groove onthe bottom side of second housing 222.

Housing 270 includes passages 280. Passages 280 extend from a secondside of housing 270 to an interior side of housing 270 adjacent secondhousing 222. Each passage 280 in housing 270 is aligned with one passage230 in second housing 222. Housing 272 includes passages 282. Passages282 extend from a bottom side of housing 282 to an interior side ofhousing 282 adjacent second housing 222. Each passage 282 in housing 272is aligned with one passage 232 in second housing 222.

Photodetectors mounting board 284 is connected to a first side ofhousing 270. Photodetectors mounting board 284 is an electronic boardthat includes photodetectors 286. Each photodetector 286 onphotodetectors mounting board 284 is positioned in one passage 280 inhousing 270. Gasket 288 is positioned between photodetectors mountingboard 284 and housing 270. Light-emitting diodes mounting board 290 isattached to a bottom side of housing 272. Light-emitting diodes mountingboard 290 is an electronic board that includes light-emitting diodes292. Each light-emitting diode 292 on light-emitting diodes mountingboard 290 is positioned in one passage 282 in housing 272. Gasket 294 ispositioned between light-emitting diodes mounting board 290 and housing272.

As seen in FIGS. 6A-10C, optical assembly 124 can excite and detectemissions from a biological sample and reagent mixture in tube array 108that is positioned in optical assembly 124. Light-emitting diodes 262are bi-color light-emitting diodes that can emit radiation at twodifferent wavelengths. In the embodiment shown, light-emitting diodes262 are blue and amber bi-color light-emitting diodes to exciteFluorescein amidite (FAM) fluorescence dye and 6-Carboxyl-X-Rhodamine(ROX) fluorescence dye, respectively. Further, light-emitting diodes 262emit radiation at a predetermine cycle rate of 1.54 kHz. Radiation fromlight-emitting diodes 262 can pass through passages 252, excitationfilter 248, passages 228, and passages 200 into the biological sampleand reagent mixture in tube array 108 that is held in wells 196.Excitation filter 248 is a dual bandpass excitation filter that iscapable of passing either of the wavelengths emitted by light-emittingdiodes 262. Excitation filter 248 is a single filter that extends acrossthe entire length of tube array 108, thus excitation filter 248 extendsbetween adjacent passages 228 in first housing 220. Radiation fromlight-emitting didoes 262 can excite a fluorescent dye in the biologicalsample and reagent mixture. This excitation of the fluorescent dye willemit a signal from the biological sample and reagent mixture and theemission can pass through passages 198, passages 226, emission filter244, and passages 250 to be detected by photodetectors 256. Emissionfilter 244 is a dual bandpass emission filter in the embodiment shown.Emission filter 244 is a single filter that extends across the entirelength of tube array 108, thus emission filter 244 extends betweenadjacent passages 226 in first housing 220.

Light-emitting diodes 292 are light-emitting diodes that can emitradiation at a single wavelength spectrum. In the embodiment shown,light-emitting diodes 292 are green light-emitting diodes to excite6-carboxy-X-hexachlorofluorescein (HEX) fluorescence dye. Further,light-emitting diodes 292 emit radiation at a predetermine cycle rate of1.54 kHz. Radiation from light-emitting diodes 292 can pass throughpassages 282, excitation filter 278, passages 232, and passages 204 intothe biological sample and reagent mixture in tube array 108 that is heldin wells 196. Excitation filter 278 is a single bandpass filter that iscapable of passing the wavelength emitted by light-emitting diodes 292.Excitation filter 278 is a single filter that extends across the entirelength of tube array 108, thus excitation filter 278 extends betweenadjacent passages 232 in second housing 222. Radiation fromlight-emitting didoes 292 can excite a fluorescent dye in the biologicalsample and reagent mixture. This excitation of the fluorescent dye willemit a signal from the biological sample and reagent mixture and theemission can pass through passages 202, passages 230, emission filter274, and passages 280 to be detected by photodetectors 286. Emissionfilter 274 is a single bandpass filter in the embodiment shown. Emissionfilter 274 is a single filter that extends across the entire length oftube array 108, thus emission filter 274 extends between adjacentpassages 230 in second housing 222.

In an alternate embodiment, light-emitting diodes 292 can be bi-colorlight-emitting diodes that can emit radiation at two differentwavelengths. Further, excitation filter 278 can be a dual bandpassfilter that is capable of passing both of the wavelengths emitted bylight-emitting diodes 292, and emission filter 274 can also be a dualbandpass filter. This would result in modular testing device 100 beingcapable of testing four different fluorescent dyes that can be mixed inwith the biological sample and reagent mixture.

Light-emitting diodes 262 and light-emitting diodes 292 emit radiationin the form of light that is cycled at a predetermined rate of 1.54 kHz.This causes emissions from the biological sample and reagent mixture atthe same predetermined rate. Photodetectors 256 and photodetectors 286thus receive the emissions from the biological sample and reagentmixture at a rate of 1.54 kHz as well. The electronic circuitryconnected to photodetectors 256 and photodetectors 286 is designed toelectronically filter out all other frequencies except for 1.54 kHz.This will negate any ambient light or other radiation sources in modulartesting device 100 that may interfere with the accuracy of the testing.

Having a single filter for emission filter 244, excitation filter 248,emission filter 274, and excitation filter 278 simplifies the design ofmodular testing device 100. This simplified design makes modular testingdevice 100 more suitable for use in the field. If one of emission filter244, excitation filter 248, emission filter 274, or excitation filter278 had to be replaced, it would be easy to replace the entire filterinstead of a number of different individual filters. Further, using onefilter for each of emission filter 244, excitation filter 248, emissionfilter 274, or excitation filter 278 reduces the cost of modular testingdevice 100.

FIG. 11 is a flowchart showing steps for operating modular testingdevice 100. The flowchart includes steps 300-316.

Step 300 includes preparing a biological sample and reagent mixture fortesting. The reagent mixture can contain the master mix necessary forthe desired assay, including fluorescent dyes or markers such as FAM orROX, necessary for detecting the desired analyte in modular testingdevice 100. Once a user acquires a biological sample, the biologicalsample can then be mixed with a reagent to form a biological sample andreagent mixture. More specifically, the biological sample is first mixedwith a reaction buffer. Next, a portion of the biological sample andreaction buffer mixture is transferred to a sample holder containing adried down master mix. This forms the biological sample and reagentmixture for testing. The biological sample and reaction mixture can betested in the sample holder containing the dried down master mix ortransferred to a different sample holder for testing.

In step 302, both the base unit and expansion unit 106 are turned on. Instep 304, a test protocol is selected in the base unit. This can be doneby scanning a code with machine readable code reader 154. The code willcontain information about what test protocol is to be run and whatparameters should be used. The test protocol can also be selected on thedisplay of the base unit and the parameters can be inputted into thebase unit. Step 306 includes communicating the selected test protocolfrom the base unit to expansion unit 106. Expansion unit 106 can thenbegin heating to the required temperature for the selected testprotocol. When expansion unit 106 is preheated, it can communicate withthe base unit. The base unit will visually and audibly notify the userthat expansion unit 106 is ready for testing. In step 308, the useropens lid 156 of expansion unit 106 and places the sample holder withthe biological sample and reagent mixture into heating assembly 170 inexpansion unit 106.

In step 310, the user begins the excitation and detection sequence forthe desired assay using the user interface on the display of the baseunit. The base unit then communicates with expansion unit 106 toindicated to expansion unit 106 that testing can begin. Optical assembly124 in expansion unit 106 then begins the excitation and detectionsequence. Step 312 includes collecting data from the biologicals sampleand reagent mixture in expansion unit 106 during the excitation anddetection sequence. Step 314 includes communicating the data fromexpansion unit 106 to the base unit. Data is transmitted from opticalassembly 124 to electronic assembly 162 in expansion unit 106. The datacan be processed by electronic assembly 162 in expansion unit 106 beforebeing communicated to the base unit. Electronic assembly 162 inexpansion unit 106 then communicates the data to an electronic assemblyin the base unit. Step 316 includes processing the data in the baseunit. The processed data can then be displayed in the base unit to theuser.

Steps 312, 314, and 316 can be done in real-time as data is beingcollected form the biological sample and reagent mixture in expansionunit 106. The electronic assembly and the display in the base unit canalso log the data received from expansion unit 106 and monitor the datafor threshold activity. Once the assay is complete, the display signalsa positive, negative, or indeterminate outcome to the user. Theelectronic assembly of the base unit can also store the data obtainedfor retrieval or transfer.

Steps 300-316 described above apply to both base unit 102 and base unit104. If base unit 102 is used, additional testing can be conducted inbase unit 102 at the same time as testing is being conducted inexpansion unit 106. Base unit 102 can be preheated at the same time asexpansion unit 106, and lid 120 of base unit 102 can be opened so that asample holder containing a biological sample and reagent mixture can beplaced in heating assembly 10 of base unit 102. Further, base unit 102can begin the excitation and detection sequence for the desired assay atthe same time as expansion unit 106 and data can be collected biologicalsample and reagent mixture in base unit 102. Base unit 102 can displaythe data collected in base unit 102 and expansion unit 106 on display116.

While the invention has been described with reference to an exemplaryembodiment(s), it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed, but that theinvention will include all embodiments falling within the scope of theappended claims.

1. (canceled)
 2. An expansion unit for a modular testing system, theexpansion unit comprising: a housing; a receptacle configured to receivea sample holder containing a biological sample and reagent mixture; anelectronic assembly within the housing, and an optical assembly withinthe housing, wherein the optical assembly of the expansion unit includesan excitation filter extending across the entire optical assembly and anemission filter extending across the entire optical assembly, whereinthe optical assembly is configured to amplify and detect a signal fromthe biological sample and reagent mixture, and wherein the electronicassembly is configured to communicate data collected in the opticalassembly to a base unit.
 3. The expansion unit of claim 2, wherein theelectronic assembly is configured to communicate with the base unit overa hard wire connection.
 4. The expansion unit of claim 3, wherein theexpansion unit does not comprise a power supply, and wherein theelectronic assembly is configured to receive power from a power supplyof the base unit.
 5. The expansion unit of claim 2, wherein theelectronic assembly is configured to communicate with the base unit overa wireless connection.
 6. The expansion unit of claim 2, wherein theelectronic assembly is configured to communicate with a second expansionunit substantially identical to the expansion unit, and the electronicassembly is configured to communicate information from the secondexpansion unit to the base unit.
 7. The expansion unit of claim 2,wherein the base unit configured to communicate with the expansion unitcomprises: a second housing comprising an integrated touchscreendisplay; a second receptacle configured to receive a second sampleholder containing a second biological sample and reagent mixture; and asecond optical assembly positioned in the second housing, wherein thesecond optical assembly is configured to amplify and detect a secondsignal from the second biological sample and reagent mixture; and ansecond electronic assembly configured to receive data from the opticalassembly of the expansion unit and the second optical assembly andconfigured to transmit the received data for display on the touchscreendisplay; and a power supply in the second housing to power the baseunit.
 8. The expansion unit of claim 7, wherein the housing of theexpansion unit does not comprise an integrated touchscreen display. 9.The expansion unit of claim 7, wherein the electronic assembly of theexpansion unit is configured to received instructions from the secondelectronic assembly based on user input received on the touchscreendisplay of the base unit.
 10. The expansion unit of claim 7, wherein thesecond optical assembly of the base unit is substantially identical tothe optical assembly of the expansion unit.
 11. The expansion unit ofclaim 2, wherein the base unit is a computer selected from a groupconsisting of a desktop computer, a laptop computer, a tablet computer,a mobile phone, a smart watch, and an embedded PC.
 12. The expansionunit of claim 2, wherein the housing of the expansion unit does notcomprise an integrated touchscreen display.
 13. A modular testing systemcomprising: a base unit comprising: a first housing comprising anintegrated touchscreen display; a first receptacle configured to receivea first sample holder containing a first biological sample and reagentmixture; and a first optical assembly positioned in the first housing,wherein the first optical assembly is configured to amplify and detect afirst signal from the first biological sample and reagent mixture; andan expansion unit configured to communicate with the base unit, whereinthe expansion unit comprises: a second housing, distinct from the firsthousing, wherein the second housing does not comprise an integratedtouchscreen display; a second receptacle configured to receive a secondsample holder containing a second biological sample and reagent mixture;and a second optical assembly positioned in the second housing, whereinthe second optical assembly is substantially identical to the firstoptical assembly and is configured to amplify and detect a second signalfrom the second biological sample and reagent mixture, wherein the baseunit further comprises a first electronic assembly, wherein theexpansion unit further comprises a second electronic assembly, andwherein the second electronic assembly is configured to receive datafrom the second optical assembly and transmit the received data to thefirst electronic assembly, and the first electronic assembly isconfigured to transmit the data from the second electronic assembly fordisplay on the touchscreen display.
 14. The modular testing system ofclaim 13, wherein the first electronic assembly is configured to receivedata from the first optical assembly and transmit the data from thefirst optical assembly for display on the touchscreen display.
 15. Themodular testing system of claim 13, wherein the first optical assemblyand the second optical assembly each comprise: a heating componentconfigured to heat the first and second biological sample and reagentmixtures in the first and second sample holders respectively; aplurality of light-emitting diodes configured to excite the first andsecond biological sample and reagent mixtures in the first and secondsample holders respectively, wherein the plurality of light-emittingdiodes are positioned on a first side of excitation filters extendingacross the entire first and second optical assemblies, respectively, andwherein the first and second sample holders are positioned on a secondside of the respective excitation filters; and a plurality ofphotodetectors configured to detect signals from the first and secondbiological sample and reagent mixtures in the first and second sampleholders, respectively, wherein the plurality of photodetectors arepositioned on a first side of emission filters extending across theentire first and second optical assemblies, respectively, and whereinthe first and second sample holders are positioned on a second side ofthe respective emission filters.
 16. The modular testing system of claim13, wherein the first optical assembly and the second optical assemblyare substantially identical.
 17. The modular testing system of claim 13,wherein the base unit further comprises: a power supply in the housingto power the base unit configured to provide power to the expansionunit.
 18. A method of analyzing a biological sample and reagent mixturewith a modular testing system , the method comprising: preparing abiological sample and reagent mixture for testing and placing thebiological sample and reagent mixture in a sample holder; placing thesample holder in a receptacle in an expansion unit, wherein theexpansion unit comprises a first optical assembly; receivinginstructions from a base unit, separate from the expansion unit, tobegin an excitation and detection test sequence with the opticalassembly of the expansion unit to analyze the biological sample andreagent mixture in the expansion unit, wherein the base unit comprise asecond optical assembly substantially identical to the first opticalassembly; collecting data from the biological sample and reagent mixturein the first optical assembly of the expansion unit; and communicatingthe data from the expansion unit to a base unit.
 19. The method of claim18, wherein the first and second optical assemblies each comprise anexcitation filter extending across the entire respective opticalassembly and an emission filter extending across the entire respectiveoptical assembly.
 20. The method of claim 18, wherein the instructionsreceived from the base unit are based on user input received from atouchscreen display of the base unit, and wherein the expansion unitdoes not comprise a touchscreen display.
 21. The method of claim 20,wherein communicating the data from the expansion unit to the base unitincludes communicating the data over a wireless connection between theexpansion unit and the base unit.